/*
 * Copyright 2015 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef SkImageShader_DEFINED
#define SkImageShader_DEFINED

#include "include/core/SkFlattenable.h"
#include "include/core/SkImage.h"
#include "include/core/SkM44.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkSamplingOptions.h"
#include "include/core/SkTypes.h"
#include "src/shaders/SkShaderBase.h"

class SkArenaAlloc;
class SkMatrix;
class SkReadBuffer;
class SkShader;
class SkWriteBuffer;
enum class SkTileMode;
struct SkStageRec;

class SkImageShader : public SkShaderBase {
public:
    static sk_sp<SkShader> Make(sk_sp<SkImage>, SkTileMode tmx, SkTileMode tmy, const SkSamplingOptions &,
        const SkMatrix *localMatrix, bool clampAsIfUnpremul = false);

    static sk_sp<SkShader> MakeRaw(sk_sp<SkImage>, SkTileMode tmx, SkTileMode tmy, const SkSamplingOptions &,
        const SkMatrix *localMatrix);

    // TODO(skbug.com/12784): Requires SkImage to be texture backed, and created SkShader can only
    // be used on GPU-backed surfaces.
    static sk_sp<SkShader> MakeSubset(sk_sp<SkImage>, const SkRect &subset, SkTileMode tmx, SkTileMode tmy,
        const SkSamplingOptions &, const SkMatrix *localMatrix, bool clampAsIfUnpremul = false);

    SkImageShader(sk_sp<SkImage>, const SkRect &subset, SkTileMode tmx, SkTileMode tmy, const SkSamplingOptions &,
        bool raw, bool clampAsIfUnpremul);

    bool isOpaque() const override;

    ShaderType type() const override
    {
        return ShaderType::kImage;
    }

    static SkM44 CubicResamplerMatrix(float B, float C);

    SkTileMode tileModeX() const
    {
        return fTileModeX;
    }
    SkTileMode tileModeY() const
    {
        return fTileModeY;
    }
    sk_sp<SkImage> image() const
    {
        return fImage;
    }
    SkSamplingOptions sampling() const
    {
        return fSampling;
    }
    SkRect subset() const
    {
        return fSubset;
    }
    bool isRaw() const
    {
        return fRaw;
    }

private:
    SK_FLATTENABLE_HOOKS(SkImageShader)

    void flatten(SkWriteBuffer &) const override;
#ifdef SK_ENABLE_LEGACY_SHADERCONTEXT
    Context *onMakeContext(const ContextRec &, SkArenaAlloc *storage) const override;
#endif
    SkImage *onIsAImage(SkMatrix *, SkTileMode *) const override;

    bool appendStages(const SkStageRec &, const SkShaders::MatrixRec &) const override;

    sk_sp<SkImage> fImage;
    const SkSamplingOptions fSampling;
    const SkTileMode fTileModeX;
    const SkTileMode fTileModeY;

    // TODO(skbug.com/12784): This is only supported for GPU images currently.
    // If subset == (0,0,w,h) of the image, then no subset is applied. Subset will not be empty.
    const SkRect fSubset;

    const bool fRaw;
    const bool fClampAsIfUnpremul;

    friend class SkShaderBase;
    using INHERITED = SkShaderBase;
};

#endif
